aquaponics – vegetable and fish co-production 2013 · aquaponics combines hydroponic plant...
TRANSCRIPT
Aquaponics –
Vegetable and Fish Co-Production 2013
Richard TysonUniversity of Florida
Orange County Extension Service
INTRODUCTION
Sustainable agriculture combines plant and animal production, integrates natural biological cycles, and makes the most use of nonrenewable resources (USDA 1990 Farm Bill).
INTRODUCTION
Aquaponics is a sustainable system that integrates hydroponic (plant) and aquaculture (animal) systems.
Uses natural biological cycles (Nitrification)
Conserves nitrogen - fish waste nutrients are taken up by plants reducing fertilizer inputs.
Aquaponic Systems
NFT Floating raft Bench Bed
Crop and Fish Choices
Leafy salad crops, herbs, tomato, pepper, and cucumber
Tilapia, rainbow trout, largemouth bass, yellow perch, bluegill, Barramundi, koi and other ornamental fish
System Water Quality
pH, 7.0 – 7.5
Oxygen, 5 ppm or greater
Ammonia, 1 ppm or less
Sunlight + Nutrient rich water = algae
Water Quality Measurements
pH
Ammonia
Dissolved Oxygen
Soluble Salts
Alkalinity
Nitrate
Aquaponics Nitrogen CycleAquaponics Nitrogen Cycle
Nitrogen from Fish Feed
In aquaculture, the generation of NH3
-N in recirculating water through fish waste is based on the fish feeding rate:
P TAN = F x PC x 0.092
T
F = feed weight, PC = % protein content of the feed, T (time) = 1 d.
1 kg of fish feed with 30% protein will produce 27.6 g of N in 1 d
Or 10% of the protein in the feed becomes nitrogen in the water!
Total Ammonia Nitrogen TAN = NH4
+- N + NH3
– N
NH4+
= NH3
+ H+
NH3
= 0.2% ↔
2% ↔
18%pH 6.5 7.5 8.5
pH Determines Ammonia Equilibrium in Water
HydroponicPlants = 5.5-6.5
Aquaculture = 6.5-8.5
N. Bacteria = 7.5-9.0
The Dichotomy of pH Optima for 3 Organisms
NITRIFYING BACTERIA
Nitrification maintains water quality by oxidation of ammonia to nitrate (Nitrosomonas sp. + Nitrobacter sp.)
NH3
+ 1½
O2
→
NO2-
+ H+
+ H2
O Eq 1
NO2-
+ ½
O2
→
NO3-
Eq 2
Measure substrate loss, product accumulation
Water pH Affects TAN Loss From Recirculating Tanks With Perlite Biofilters Inoculated With Nitrifying Bacteria
Error bars represent ± SE (n=8).
Biofilter Performance as measured by TAN Removal
0 20 40 60 80 100
6-aqpon
7-aqpon
8-aqpon
6-hc
7-ac
pH &
Pro
duct
ion
Met
hod
g/m3/d
Soluble Salts
Plants need balanced nutrition which can nearly be supplied by fish waste
Recirculating vs. intermittent nutrient application
Leafy salad crops & herbs vs fruiting crops
‘Fitness’
Cucumber Fruit Yield (kg/plant) Response to pH and Production Method
6.0-aqpon 1.52 a 3.64 a 0.44 a
7.0-aqpon 1.32 a 4.12 a 0.33 a
8.0-aqpon 0.67 b 3.54 a 0.33 a
Contrast L**
6.0-hc 1.57 a 3.63 a 0.53 a
E. Mkt. T. Mkt. T. Cull
System Sizing
Basic System S&S Aquafarms
Aquaponics Aquaponics -- ApplicationApplication
Target pH should be between 7.0 – 8.0
It depends on ammonia level (2ppm) and condition of fish and plants – I-4 Rush Hour
Foliar or root feed plants to overcome deficiencies
Reduce feeding and or increase water discharge and replacement to lower ammonia
Aquaponics Aquaponics -- ApplicationApplication
A thorough knowledge of the organisms in the system is required for success.
Juggles balance between ideal water quality conditions for the growth of fish, plants, and nitrifying bacteria.
Aquaponics research is on going
Stacked System $75/m2
+ $25/m2 = $100/ m2 /Time? Add float system or fill and drain system to increase plant area?
System Sizing – Triple Crop?
So Why Aquaponics ?
– The Water Budget!
Plants transpire lg amounts of water (1pt - 6 qt/d/pl).
Recirculating aquaculture replaces 5 to 10% of system water/day to maintain water quality.
Potential for zero discharge to the environment
So Why Aquaponics ?
-The Nitrogen Budget!
Fish produce large amounts of ammonia nitrogen as waste which is harmful
One plant uses 1 (lettuce) to 20 (tomato) grams of nitrogen per season
100 lbs of fish will supply enough nitrogen for 4,050 lettuce plants or 540 tomato plants
Marketing
USDA wholesale price market reports – do not compete with field grown on the wholesale level
Get as close to retail pricing with on-farm sales, high end food stores, restaurants and farmers markets
Regulations - Aquaponics
Farm food safety audits are currently required by big box stores for vegetables
Vegetables may be sold to buyers who do not require the audit
Ensure that the vegetable part being eaten does not contact the water
Regulations - Aquaculture
Pond side whole – few
Blue Tilapia – few, live or dead
Nile Tilapia – should be dead unless buyer has a license from FDACS Fish & Game
Any knife or filleted – Many food safety regulations for handling & storage
Uncertainty, high cost, regulations, do your research!
Aquaponic Resources
Harbor Branch Oceanographic Institute http://www.fau.edu/hboi/
Aquatic Eco-systems, Inc. http://www.aquaticeco.com/
Blackwater Creek Koi Farms http://www.koisale.com/
Aquasafra, Inc. http://www.tilapiaseed.com/